The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 06, 2002
Filed:
Feb. 23, 2001
Michihiko Yanagisawa, Sagamihara, JP;
Tadayoshi Okuya, Yokohama, JP;
SPEEDFAM Co., Ltd., Ayase, JP;
Abstract
A discharge tube for a local etching apparatus has a portion positioned within a waveguide which is for the generation of plasma, the said portion being tapered so as to be divergent toward an orifice side of the discharge tube. Even in the event a maximum field strength position of a standing wave in the waveguide should be deviated due to a change in microwave transmission characteristic of the material of the discharge tube or a change in the position of a plunger under the influence of heat, the maximum field strength position lies somewhere in the vicinity of a wall surface of the tapered portion, so that a supplied gas is converted to plasma stably in a short time. When the discharge tube is to be cooled, the cooling can be done effectively with a cooling gas which is cooled by adiabatic expansion while passing through the tapered portion.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile